Control device for refrigerating systems



July 11, 1939. R. E. STOLZ CONTROL DEVICE FOR REFRIGERATING SYSTEMSOriginal Filed May 4, 1955 3 Sheets-Sheet l INVENTOR. Zlg'usEfita/z. M

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ATTORNEY.

CONTROL DEYICE FOR REFRIGERATING SYSTEMS Original Filed May 4, 1935 3Sheets-Sheet 2 y 1939- R. E. STOLZ 2,165,518

CONTROL DEVICE'FOR REFRIGERATING SYSTEMS Original Filed May 4, 1935 3Sheets-Sheet 3 IIIIIIIIIIIIIAI: as 223 21 224 221 7 INVENT OR. Rafael..Stolz.

UNITED STATES PATENT OFFICE CONTROL DEVICE FOR REFRIGERATING SYSTEMSRufus E. Stolz, East Cleveland, Ohio Original application May 4, 1935,Serial No. 19,819. Divided and this application January 4, 1939, SerialNo. 249,322

25 Claims.

This application is a division of the application Serial No. 19,819filed by me on May 4, 1935, for Control devices.

My invention relates to refrigeration systems, and more particularly tocontrolling the flow of refrigerants by means of valves and othercontrol devices.

One object of my invention is the provision of a thermally actuatedvalve mechanism for controlling the flow of a refrigerant through anevaporator in accordance with the temperature conditions.

Another object of my invention is the provision of cooling a fluiddischarge pipe or conduit and of controlling the degree of cooling by athermally actuated valve mechanism.

Another object of my invention is to limit the growth of frost on arefrigerator evaporator by the action of a temperature responsive devicecontrolling the flow of the refrigerant.

Another object of my invention is to control the temperature of arefrigerator evaporator by a temperature responsive device which isinfluenced by the temperature of the said evaporator.

Still another object of my invention is to control the temperature andfrosting of an evaporator by a temperature responsive device whichactuates a valve which allows or prohibits the flow of refrigerantthrough the evaporator,

Still another object of my invention is to provide a refrigeratingsystem which will not only cool the liquid in a liquid container, butcool the liquid in the discharge pipe or conduit between the containerand the discharge valve.

I A still further object of my invention is to provide a closedrefrigerant circuit through an evaporator and to regulate the flow ofthe refrigerant through that circuit by the use of several temperatureresponsive devices and valves, one temperature responsive device andvalve to limit the frosting of the exit side of the evaporator, andanother temperature responsive device and valve to admit the refrigerantto the evaporator in an 45 operating cycle thereby accuratelycontrolling the temperature of the evaporator.

A further object of my invention is to provide for controlling the flowof a refrigerant through an evaporator by the resultant pressure ofseveral 50 pressure means actuated by pressure from difierent points onthe .evaporator. I

A further object of my invention is to provide for controlling thetemperature of a closed refrigerant circuit having an evaporator by the55 action on a valve of the pressure resultant of several opposingpressures from different points in the refrigerant circuit.

Another object of my invention is to provide for sealing a valve in avalve casing by means of a flexible wall and for actuating the valve bymeans externally of the valve casing through means of the flexible wall,thereby effecting substantially a hermetically sealed valve.

Another object of my invention is the provision of a valve and a valvecasing for controlling the flow of a medium, and a flexible meansadapted to guide the valve and to entrap the medium from escaping fromthe valve casing past the valve in which case the medium exerts aninternal pressure upon the flexible means and thereby urges the movementof the valve, taken in combination with equalizing means adapted tooff-set the internal pressure of the medium upon the flexible means andthereby make the movement of the valve independent of the internalpressure of the medium acting upon the flexible means.

A still further object of my invention is the provision of actuating avalve for controlling the flow of a medium, wherein the mediuminfluences the actuating means for the valve, taken in combination withan equalizing means adapted to off-set the influence of the mediumacting upon the actuating means of the valve.

Another object of my invention is to prevent too much ice collectingupon an evaporator of a refrigerating system by controlling the flow ofthe refrigerant to the evaporator in accordance with temperatureconditions.

A still further object of my invention is the provision of a pressureactuated snap valve mechanism for controlling the flow of a refrigerantto an evaporator, in accordance with the pressure conditions of therefrigerant.

Another object of my invention is the provision of a pressure actuatingdevice for controlling a switch for interrupting the flow of current,taken in combination with an emergency pressure operating means foropening the switch when the pressure exceeds a predetermined selectedvalue.

. Another object of my invention is the provision of a pressure actuatedsnap valve mechanism for controlling the flow of cooling water, whereinthe water either is flowing substantially full force or is substantiallyshut off, by reason of the snap action of the valve.

Other objects and a fuller understanding of my invention may be had byreferring to the following description and claims, taken in combinationwith the following description, in which:

Figure 1 is a front view of a thermally actuated snap valve mechanism,embodying the features of my invention, parts being cut away toillustrate more clearly the construction of the working parts;

Figure 2 is a front view of a pressure actuated snap water valvemechanism, embodying the features of my invention parts being cut insection to illustrate more clearly the construction of the workingparts;

Figure 3 is a diagrammatic illustration of the floating togglearrangement, embodyingthe fea tures of my invention;

Figure 4 is a fragmentary view of the toggle arrangement shown in Figure3, and illustrates a different position of the parts than that positionillustrated in Figure 3;

Figure 5 is a front view of a pressure actuated snap valve mechanism,embodying the features of my invention, parts being cut in section toillustrate more clearly the construction of the working parts;

Figure 6 is a front view of a quick acting pressure operatedswitch,embodying the features of my invention;

Figure 7 is a diagrammatic illustration of a refrigerating system,employing features of my invention;

Figure 8 is a fragmentry diagrammatic illustration of another use of myinvention, and illustrates primarily the means for cooling the exit pipethrough which a fluid is passed before discharged from the pipe;

Figure 9 is a cross-sectional view of an evaporator which may beemployed in my-refrigerating system shown in Figure '7, and

Figure 10 is a cross-sectional view of a cleaning device which may bemounted in the fluid line of my refrigerating system, shown in Figure 7.

With reference to Figure 1 of the drawing, the reference character I0indicates, generally, my thermally actuated 'snap valve mechanism, andcomprises briefly a valve assembly having a control valve I5 and a valvecasing I8, a lower flexible wall assembly indicated generally by thereference character I, an upper neutralizing flexible wall assemblyindicated generally by the reference character I3, a thermo-expansiblefluid power device 0, and a floating toggle arrangement indicatedgenerally by the reference character I2, cooperating with thethermo-expansible power device C and having a large adjustment spring Aand a small adjustment spring B, a common interconnecting member I6which interconnects the floating toggle arrangement with the valveassembly for actuating the valve stem 26 of the control valve I5, and abody bracket 46 upon which the various parts are mounted.

The control valve I5, as will appear later in the description, isadapted to control the flow of the refrigerant to an evaporator of arefrigerating system. The refrigerant, as it comes from the compressorflows through the feed pipe 34 to a T-shaped nipple 35, thence through athimble 33 into a second T-shaped nipple 28, then past the valve I5 tothe exit pipe 32 which leads to the evaporator of the refrigeratingsystem. As illustrated, the valve I5'is adapted to cooperate with areplaceable valve seat 3I which rests on top of a restriction 30provided in the thimble 29. In actual practice, the replaceable valveseat 3I is constructedof stainless steel, in order to avoid corrosionwhich would, if allowed to occur, impair the operation of the controlvalve I5. The control valve I5 is provided with a valve stem 26 which isconnected to the plunger 20 of the bellows I9 by means of a threaded end21. Therefore, the bellows I9 constitutes a support for guiding thevalve I5 with reference to the valve seat 3I. This means that the valvestem 26 is entirely free to move up and down to control the flow of therefrigerant to the evaporator of the refrigerating system, except forthe small amount of power required to'move the bellows I1 and I9.Surrounding the bellows I9, is a valve casing I8 having a femalethreaded opening which threadably engages the upper threaded end of theT-shaped nipple 28. The upper end of the bellows casing I8 may beconnected to-the under side of the lower flange 48 of the body bracket46 by means of the four interconnecting members 43. This constructionprovides for sealing the valve IS in a valve casing by means of aflexible wall and for actuating the valve I 5 by means externally of thevalve casing, thereby effecting substantially a hermetically sealedvalve. This is very important, for the reason that if the valve stem 26had to extend through the usual valve packing for external operation,the said packing would have to be so tight to prevent leaking of therefrigerant past the valve stem that the up and down movement of thevalve stem would be very stiff, making it impossible to operate it bythe thermo-expansible fluid power device C. With this construction,however, the refrigerant exerts an internal pressure against the bellowsI9, and thus tends to urge the valve stem 26 upwardly to open the valveI5. To off-set the effect of the internal pressure of the refrigerantacting upon the flexible wall bellows I9, I utilize an upperneutralizing flexible wall assembly I3, having a flexible wall bellowsII, which is of a construction similar to the construction of theflexible wall bellows I9. As illustrated, the flexible wall bellowsI'I,;is enclosed in a casing I I which is connected in communicationwith the T-shaped nipple 35 by means of an interconnecting pipe 36. Theplunger II of the upper flexible Wall bellows IT projects downwardlythrough the upper flange 41 of the body bracket 46, and engages anadjusting nut 25 which threadably engages the upper end of the threadedfloating stud 2 I. Upon the lower end of the threaded floating stud 2|is an adjusting nut 24 which contacts the upper end of the plunger 20that is actuated by the flexible wall bellows I9. Intermediate thefloating threaded stud 2| are two jam nuts 22 and 23 which engage thecommon interconnecting member I6 which interconnects the togglearrangementindicated generally by the reference character I2 to thefloating stud 2|. By the foregoing arrangement, it is noted that thedownward force produced by the upper neutralizing flexible wall bellowsI1 is equal to the upward force produced by the flexible wall bellowsl9. This means that themovement of the valve I5 is independent of thepressure of the refrigerant, and thus the operation of the valve I5 iscontrolled entirely by the force produced by the toggle arrangementindicated generally by the reference character I2.

While I have illustrated the neutralizing flexible wall bellows II asbeing mounted above and in vertical alignment with the flexible wallbellows I9, yet it is to be understood that the neutralizing flexiblewall bellows I! may be mounted in any opposing cooperative relationshipwith the flexible wall bellows I9. Thus, the neutralizing flexible wallbellows II may be mounted off to one side of the flexible wall bellowsI9 and arranged to set up an opposing force through means of a lever; 75

system, such as, for example, through means of a walking beam type ofconstruction of levers.

As illustrated, the thermo-expansible fluid power device C is connectedin communication with a thermo-expansible fluid tube 31 by means -of atube 38. In actual practice, the thermoexpansible fluid tube 31 isprovided with an expansible fluid, and accordingly the pressure exertedby the expansible fluid is a function of the temperature surrounding theexpansible fluid tube. As will appear later in the description, thisexpansible fluid tube may be placed adjacent or in the vicinity of anevaporator of a refrigerating system, so that the pressure exerted bythe expane sible fluid is a function of the temperature condition,of theevaporator and the surrounding circulating air. While not shown incross-section, the thermo-expansible power device C may be constructedof a bellows similar to the flexible wall bellows l1 and I9. Therefore,the variable force exerted ,by the thermo-expansible fluid 'power deviceC is a function of the temperature conditions surrounding thethermo-expansible fluid tube 31.

The thermo-expansible fluid power device C is attached to the lowerflange 48 by the screws 49 and is arranged to exert a variable forceupon 7 the'floating toggle arrangement indicated generally by thereference character I2, and is disposed to work in opposition to thelarge adjustment spring A. See Figures 1, Band 4. The construction ofthe parts which interconnect the thermo-expansible fluid power device Cwith the large adjustable spring A maybe explained as follows:Immediately above the thermo-expansible fluid power device C andpartially projecting through the lower flange 48 of the body bracket 46,is a stop nut 39 which threadably engages a plunger 49 that is operatedby the thermoexpansible fluid power device C. This plunger 49 extendsthroughout the length of the toggle assembly I! and terminates at apoint above the upper flange 41. Immediately above the threaded stop nut39 and surrounding the plunger 49 is a rectangular block 59, against theupper edge of which, and surrounding the plunger 49, is placed the lowerflange 53 of the interconnecting member. IS. A tubular sleeve 62surrounding the plunger 49, is arranged between the lower flange 63 andthe upper flange of the interconv wis a jam nut 55. Therefore, when thejam nut 65 and the stop nut 39 are tightly turned down, the entireassembly of the parts associated with the plunger 49 becomes securelyand rigidly connected to the plunger 49. The sleeve 63 is primarilyutilized in order to aiford a good strong support for theinterconnecting member 16, so

that there is no tendency for the interconnecting member l6 to becomeloose and have play with reference to the plunger 49. As illustrated,the large spring A is interposed between the upper flange 41 and anadjusting nut 66, so that the force of the large spring A may be variedby turning the adjusting nut 66. Above the flange 41 and threadablyengaging the plunger $49-15 a. jam nut.14 anda jam nut 13 between whichis mounted an upper floating block 68 having a longitudinal groove 69provided on the right-hand longitudinal side thereof. Above the flange41 there is also provided a stationary block 10 having a groove 12.Positioned in the two grooves 59 and 12 is a knife edged member 1|Ifiwhich pivots up and down as the plunger 49 is moved. In order to holdthe knife edged member H within its associated grooves, I utilize acurved wire spring 15 having its left-hand end engaging the upper end ofthe plunger 49 and having its right-hand end engaging a stationaryanchoring stud 16 mounted on top of the stationary block 10.Consequently, the combined action of the knife edged member 1| and thespring 15 is such as to guide the upper end of the plunger 49 while atthe same time affording an up and down movement to the plunger that issubstantially free of friction. The upward travel of the plunger 49 maybe determined by the head of the stop nut 39 engaging the under surfaceof the lower flange 48 and the downwardtravel may be determined by therectangular block 59 engaging the upper side of the flange 48.

With reference to the floating block 50, there is provided along itsleft-hand longitudinal face a groove 55 and along its right-handlongitudinal face a groove 58. .Spaced to the left of the floatingblock59 is a stationary block which has along its right-hand longitudinalface a groove 54, and spaced to the right of the floating block 50 is astationary block 52 having a knife-edge member 6| projecting from thelefthand longitudinal face thereof. Positioned in the longitudinalgroove 54 of the stationary block El and the longitudinal groove 55 inthe lefthand longitudinal face of the floating block 59 is a knife edgedmember 51. As illustrated, there is an inverted L-shaped lever 53 havingalong its inside lower longitudinal edge thereof, a groove 42.Interposed between the longitudinal groove 42 and the groove 58 of thefloating block 50 is a knife-edge member 59. The right-hand outer edgeof the inverted L-shaped lever 53 is provided Witl a longitudinal groove60 in which is positioned the left-hand edge of the knife-edged memberBI. The left-hand end of the inverted L-shaped lever 53 is urgedupwardly by means of a small adjusting spring-B which has its upperend'thereof provided with a threaded nut adapted to receive the threadsof the adjusting screw 61, which varies the tension of the adjustingspring B as it is turned. It is noted that the arrangement ofthe'inverted L-shaped lever 53, together with its associated parts,provides a toggle arrangement having a knee-action, to give a quickacting movement to the plunger 49. It is also noted that the togglearrangement afforded by the plunger 49, is such as to provide a guidearrangement for the plunger 49 which is substantially free of friction.Therefore, my entire toggle assembly may be referred to as a floatingguide arrangement. the floating toggle arrangement more than offsets thesmall amount of power required to move the flexible wall bellows I 1 andI 9. In other words, the floating toggle arrangement has been made tomove very freely to compensate for the power required to move theflexible wall bellows and I9. The construction of my entire togglearrangement is shown diagrammatically in Figures 3 and 4.

In the study of this diagrammatic showing, it is noted that when theknee-action produced by the knife-edged members 51 and 59 issubstantially straight, there is substantially no urging force producedby the small spring 13 to move the plunger 49. This position isillustrated in Figure 3. On the contrary, it is noted with ref- Theabsence of friction in produced by the knife-edge members 51 and 59 isbiased, there is an urging force produced by the small adjusting springB to urge the plunger d9 upwardly. Therefore, when the knee-actionproduced by the knife-edge members '1 and 59 59 is substantiallystraight, it is only necessary when moving the plunger 49 upwardly forthe variable force'produced by the thermo-expansible fluid power deviceC to be increased to ,a value that is slightly greater than the opposingforce produced by'thelarge adjusting spring A. This means that when thetemperature surrounding the thermo-expansible'iiuid tube 31 obtains acertain value sufficiently to cause the variable force created by thethermo-expansible fluid power device C, to be slightly greater than theopposing force set up by the large adjusting spring A, then the plunger49 is urged upwardly which trips the toggle arrangement and opens thecontrolling valve l5. This allows the refrigerant to flow to theevaporator, which in turn reduces the temperature surrounding theexpansible fluid tube 31." By this arrangement, the upper temperaturesetting at which the refrigerant is delivered to the evaporator, toproduce a cooling action, is determined by the tension of the largeadjusting spring A efiected by the turning of the adjusting nut 65.

With reference to Figure 4, it is noted that when once the plunger 49 isbiased upwardly, then the force produced by the small adjusting spring Bcomes into play, and helps to urge or snap the plunger 59 upwardly. Inother words, when the knee-action produced by the knife-edged members5'! and 59 are biased, the force produced by the small spring B opposesthe downward force produced by the large adjusting spring A. Therefore,in order to close the control valve i5 to shut off the refrigerant tothe evaporator, it is necessary that the temperature influencing thethermo-expansible fluid tube 31 be reduced to such low value that thevariable force produced by the thermoexpansible fluid power device Cplus the small ad- 'justing spring B,'be less than the force produced bythe large adjusting spring A. Accordingly, the lower temperatureat whichthe valve- I5 is closed to stop the cooling action of the evaporator ismuch lower than the temperature at which the controlling valve i5 isopened to allow refrigerant to flow to the evaporator for producingcooling action. This means that the sprea between the upper tempertureat which the control valve 15 is opened and the lower temperature atwhich the control valve is closed, is determined by the tension of thesmall adjusting spring 13. Thus, by the construction of thermallyactuated snap valve mechanismiil, it is possible to set the lowertemperature at which the refrigerant is delivered to the evaporator andthe upper temperature at which the refrigerant is shut off from theevaporator.

In Figure 2, I show the manner in which my quick-acting floating togglearrangement may be employed to operatea fluid or water valve, the entireassembly being indicated generally by the referencecharacter 8!. Thisform of my invention may be referred to as a pressure actuating snapwater valve, and comprises briefly a metallic bellows enclosed in thehousing $2, a quick acting floating toggle arrangement indicated by theref erence character 86, and a valve assembly indicated generally by thereference character 38 mounted beneath the lower flange of the bodybracket H0.

' The bellows enclosed in the housing 92 may be of a constructionsimilar to that shown in crosssection in Figure 1, and is adapted to beconnected in communication, as will appear later, with the high pressurerefrigerant-fluid line of a refrigerating system, by means of theconnecting pipe 83. Therefore, when the pressure in the refrigerantfluid line exceeds a certain predetermined limit, the valve is open toallow water to flow through the valve assembly 96 and cool off thecompressor and the condenser for llquefying the refrigerant.

The valve assembly Qiiis arranged to be mounted below the lower flangeof the body bracket I I0, and comprises in general a valve casing )6, astationary valve sleeve 95, a movable valve sleeve 91, a valve stem 9|,a rubber valve ,washer 99, and a spring 102 for urging the rubber valvewasher 99 against the lower end of the stationary valve sleeve 95. Theupper end of the valve casing I05 is enlarged and provided withfemalethreads adapted to screw upon the male threads provided on the annularflange I07 that is connected to the lower flange of the body bracket H0.As illustrated, the valve casing I06 is provided with an internalshoulder 9i! upon which is mounted a flexible rubber diaphragm disk 08.Placed on top of the circumferential edge of the diaphragm disk 88 is anannular washer 89, so that when the valve casing Ills is firmly screwedupon the annular flange ill], the rubber diaphragm disk 88 is tightlyheld between the shoulder of the valve casing 88 and the annular washer89. I

The valve stem 9i that is threadably connected to and actuated by theplunger 91 of the floating toggle arrangement as is adapted to extendthrough the central portion of the rubber diaphragm disk 88 andthreadably engage the lower end of the plunger 81 of the togglearrangement 84-. In order to provide a good seal therefor, a jam nut s3,is placed around the valve stem 9| and above the rubber diaphragm disk38, and there is placed around the valve stem 9| and below the rubber.diaphragm disk 88, a jam nut 92, so that when the two jam nuts 93 and 92are tightly turned against the rubber diaphragm disks 88, there isprovided a good tight seal. This prevents any fluid or water fromescaping past the valve stem 9i.

As shown, the upper inner surface of the valve casing M6 is providedwith female threads which are adapted to threadably receive the upperend of the stationary valve sleeve es. When the stationary valve sleeve95 is screwed into the valve casing )6, the lower end thereof isarranged to coincide with the lower enlarged end of the valve stem Siwhen the toggle arrangement is actuated to its uppermost position.Surrounding the stationary valve sleeve 95 is a movable valve sleeve atwhich is provided intermediate its ends with a circumferential shoulderiii) against which rests a.

rubber valve Washer es. Upon the underneath side of the rubber valvewasher 99 is a metal washer tilt which urges the rubber washer 3i)tightly against the lower end of the stationary valve sleeve 95 by meansof the spring use that is because there is substantially no backpressure exerted by the fluid or water when flowing. Therefore, thetoggle arrangement 84 is substantially 1 free from influence by thefluid or 'water exerting a pressure from the rubber diaphragm disk 88.The arrangement of the valve assembly 96 is such that it can be easilydismantled for cleaning purposes simply by removing the end plug I03 andthen removing theevari- Gus-parts of the valve. i

The floating toggle arrangement 84 for actuating the valve assembly 96is substantially the same as that hereinbefore described withreferadjusting spring I08 which corresponds, to the large springindicated by the reference character A in Figure 1,- and a smalladjusting spring I09 which corresponds to the small spring indicated bythe reference character B in Figure 1. The adjusting nut 85 is arrangedto control the adjustment of the large spring I08 and the adjustingscrew 86 is arranged tocontrol the adjustment of the small spring I09.Accordingly, the upper pressure exerted upon the bellows in the casing82 at which the valve assembly is open to allow the cooling water toflow therethrough and cool the compressor and condenser is determinedprimarily by the setting of the large spring I08 by the adjustment screw85, and the lower pressure exerted upon the bellows enclosed in thecasing 82 at which the valve assembly is closed to prevent the fluid orcooling water toflow there through is determined by the setting of thesmall spring I09 by the adjusting screw 86.

To facilitate the assembly of the toggle arrangement, the plunger 81 isconnected to the plunger that is actuated by the bellows bymeans of. thethreaded sleeve nut 81., In addition to the rubber diaphragm washer 88acting as a seal to prevent any fluid or water escaping past the valvestem 9I, it is noted that it provides a lower guide to the movement ofthe floating toggle arrangement.

The function of the floating toggle arrangement 84 is such as to give aquick acting snap movement to the valve, in which case the valve iseither fullyopcned or fully closed to control the flow of the coolingwater to the compressor and the condensing unit.

In Figure 5, I illustrate another form of a valve embodying the features.of my invention, which is indicated generally. by the referencecharacter I I3. This form of my invention may be referred to as apressure actuated snap refrigerant valve, and comprises in general a;body bracket I40, a floating toggle arrangement indicated generally bythe reference character I I5, a bellows enclosed within the casing I22,and a valve assembly actuated by the toggle arrangement and the bellows.

As illustrated, the bellows may be connected to the lower flange II2 ofthe body bracket I40 by means of the inner-connecting members I 2I. Thelower portion of the casing I22 is provided with female threads toreceive the upper end of a T-shaped nipple I38. Screwed to the lower endof the T-shaped nipple I38 is a nipple I36 having a valve seat I39 onwhich rests the ball valve I3I.

v find its seat I39, I utilize a yoke and pin connection I24whichconnects the valve plunger I25 to the upper plunger I23 that isconnected to the bellows enclosed within the casing I22. The

sleeve I28 is loosely connected to the valve plunger I25 by means of across pin I29 that passes through an enlarged opening I30. This meansthat there is a small amount of play between the movement of the plungerI25 and the movement of the ball valve I3 I.

The floating toggle arrangement indicated generally by the referencecharacter 4, is substantially the same as that described hereinbeforewith reference to Figures 1, 3 and 4 and comprises a large adjustingspring I I6 that correence to Figures '1, 3 and 4, and comprises a largesponds to the large spring indicated by. the reference character A inFigure 1 and a small adjusting spring I" that corresponds to the smallspring indicated by the reference character B in Figure 1. The uppersingle knife edged guiding arrangement that is mounted above the upperflange II I of the body bracket I40, is indicated generally by thereference character I31 and is substantially the same as that shownin'Figure l. The adjusting nut II5 varies the tension of the largespring IIS and the screw II8 varies the tension of the small spring 1.To facilitate the assembly, the lower plunger II9 that is actuated I bythe bellows in the casing I22 is connected to the upper plunger I bymeans of the threaded sleeve I34. The reference character I20 indicatesa stop nut for limiting the upper travel of the toggle arrangement andfor securely holding the parts to the plunger I35.

In actual practice, this form of my invention may be utilized to controlthe flow of a refrigerant in a refrigerating system, and it is notedthat the refrigerant itself in this form of my invention controls thebellows mounted in the casing I22, which, in turn, controls the flow ofthe refrigerant itself. In this connection, let itbeassumed that thepressure of the refrigerant which enters the pipe I33 flows into thevalve assembly and exerts an upper pressure upon the bellows within thecasing I22. When thispressure obtains a certain predetermined uppervalue, it causes the toggle arrangement Ill to kick upwardly and allowsthe refrigerant to flow past the ball valve I3I and out into the exitpipe I32. It is noted that upon the initial upward movement of thetoggle arrangement Ill, the spring 126 still urges the ball valve I3Iagainst its seat until the slack or play or the opening I 30 in theupper plunger I25 contacts the cross pin I29 and raises the sleeve 128.This means that there is a delay to the opening" of the ball valve I 3|,until after the floating toggle arrangement Ill is biased far enough bythe bellows enclosed within the casing I22 to carry the togglearrangement to the end of its travel. In other words, if the ball valveI3I were allowed to open immediately with a slight upward movement ofthe toggle arrangement, the refrigerant would flow past the ball valveI3I, in which case the back pressure of the refrigerant wouldimmediately be reduced to cause the ball valve I3I to close again. Thiswould cause chattering of the ball valve I3I, and in order to overcomethis, I utilize the slack or play between the cross pin I28 and theenlarged opening I3I.

general a body bracket I64, a mercury switch I41,

a bellows enclosed within the casing I53 for operating the floatingtoggle arrangement indicated generally by the reference character I42,and an emergency bellows enclosed within the casing I54 for operatingthemercury switch I41 in the event that the pressure of the fluid line I48of a refrigerating system obtains a predetermined high value.

I41 is of the usual form and is arranged to be pivotally mounted upon apivot pin HI, and is actuated by the floating toggle arrangement I42 bymeans of an actuating arm I49 which carries an adjusting screw I50having its upper end contacting a portion I10 for tilting the mercuryswitch I41 to its opened position in a counter clockwise direction whenthe movement of the toggle arrangement I42 is upwardly. In accordancewith usual practice, a weight I48 is utilized to re-tilt the mercuryswitch I41 to its closed position in a clockwise direction when thetoggle arrangement I42 is actuated to its downward position. The twolower mercury pools of the mercury switch I41 are connected respectfullyto a terminal block I6I to which are connected the control wires I59 andI60 for controlling the starting and stopping of the electric motor fordriving the refrigerating compressor.

The two bellows within the casing I53 and I54 are mounted on the upperflange I68 of a supple-. mentary body bracket I61 that is connected tothe upper flange I66 of the body bracket I64. To facilitate assembly,the plunger of the bellows within the casing I53 is connected throughmeans of the interconnecting screw sleeve I62 to the floating togglearrangement I42. The construction of the floating toggle arrangement I42is substantially the same as that shown and described in Figures 1, 3and 5 and comprises a large adjusting spring I43 and a small adjustingspring I44. The adjusting nut I45 is arranged to adjust the tension ofthe large spring I43 and the screw I46 is arranged to adjust tension ofthe small spring I44. Mounted beneath the lower flange I65 of the bodybracket I64 is the single knife edged floating arrangement, indicatedgenerally by the reference character I63.

In the operation of this switch, when the pressure of the refrigerantentering the pipe I51 exceeds a certain predetermined upper value, thebellows within the casing I53 actuates the toggle arrangementdownwardly, and thus allows the weight I48.to rotate the mercury switchI41 in a clockwise direction to close the switch and start therefrigerating compressor. When the compressor is once started, thepressure will fall until it obtains a certain predetermined lower value,and then the toggle arrangement is actuated upwardly to open the switchI41 and stop the motor from driving the refrigerator compressor. Ashereinbefore noted, the upper pressure at which the switch I41 is closedis determined by the setting of the large spring I43, and the lowerlimit at which the switch is opened is determined by the setting of thesmall spring I44. The reference character I52 indicates a stop nut forlimiting the downward travel of the toggle arrangement I42 and forsecurely holding the partsto the plunger. I

In this embodiment of the invention, there is provided an emergencybellows, within the cas- The construction of the mercury switchping thecompressor motor.

In Figure 7, I have diagrammatically illustrated a refrigerating systememploying the devices illustrated in Figures 1, 2, 5 and 6 andare'respectively indicated generally by the reference characters'I0, 8I,H3 and I.

The quick acting snap valve assembly 8|, hereinbefore noted, may beutilized as a pressure actuated snap water valve and is adapted tocontrol the flow of the cooling water to the refrigerating compressorI8I and a condenser I83.

The bellows 82 of this pressure actuated snap water valve is connectedto the high pressure refrigerant fluid line I9I of the refrigeratingsystem through means of a pipe 83. Therefore, when the pressure in therefrigerant fluid line I III attains a predetermined high value, thefloating toggle arrangement of the pressure actuated snap water valve 8Itrips and opens the valve to allow cooling water to flow from the supplypipe I85, through a pipe I04, thence through the valve assembly of thepressure actuated snap water valve 8I, the pipe I05, the water jacket ofthe refrigerating compressor I8I, and thence through a pipe I86 to thecondenser pipes I84, and then out through the exit pipe I81 to the sewerI88. As the cooling water flows through the water jacket of therefrigerating compressor I8I and the condenser pipes I84, the pressureof the refrigerant in the fluid line I9I is gradually reduced, and whenit reaches a predetermined low value, the floating toggle arrangement ofthe pressure actuated snap valve 8I trips and closes the valve to shutoff the flow of the water through the water jacket I8I and the condenserpipes I84. Accordingly, the cooling water is either flowing full forceor is shut off, by reason of the quick acting function of the floatingtoggle arrangement of the pressure actuated snap water valve 8I.

The refrigerating system shown in Figure 7 illustrates three, coolingdevices that are adapted to be controlled in accordance with myinvention. One of the cooling devices may be in the formof an ice creamcabinet, indicated generally by the reference character 206 having anice cream container 201 mounted therein. In accordance with usualpractice, the ice cream cabinet is supplied by brine and is arranged tobe cooled by an evaporator, indicated generally by the referencecharacter 208. The evaporator illustrated is of the flooded type, and isarranged to have a series of pipes I14. connected thereto and immer'sedin the brine. A cross-sectional view of the evaporator is illustrated inFigure 9. In practice, the refrigerant delivered to the evaporator 208is controlled by means of a needle valve I12 actuated by a float I13.The refrigerant, as it is delivered to the evaporator 208, is in liquidform, but as it cools the brine, it vaporizes and thereby'occupies thespace in the evaporator above the liquid level. From here it is suckedout of the evaporator through the pipes I95. The pipe connections fordelivering the refrigerant vaporized refrigerant is sucked through thepipe I95, a service valve I98,a pipe I91, a service valve I98, a pipeI99 to the crank case of the com- .pressor unit I8I; from thence thevapor refrigerant is compressed and forced back to the eva'porator 208through the pipe I90 to the condenser I83, where the vapor refrigerantis cooled and liquefied.

From the condenser I83 the fluid refrigerant is forced through a"service valve 2I3, a pipe I9I, a cleaning device 234, a pipe 232, apipe I92, a service valve 204, a pipe I58, to the evaporator 208. Solong as the compressor is driven by the electrical motor I82, the vaporrefrigerant is sucked from the evaporator 208, compressed, liquefied andredelivered to the evaporator 208 .in liquid form. In a flooded type ofevaporator,

the pressure of the vapor refrigerant is determined primarily by thetemperature of the brine. Therefore, I utilize my pressure actuatedswitch I to control the starting and stopping the electric motor I82which drives the compressor I8I, in accordance with the pressure of thevapor refrigerant in the evaporator 208. In other words,

inasmuch as the vapor pressure of the refrigerant v is a function of thetemperature of the brine, it follows that the compressor I8I iscontrolled in accordance with the temperature of the brine,

or in accordance with the duty of refrigeration.

As illustrated, the bellows in the casing I53 of the pressure operatedswitch I 4| is connected in communication, with the service valve thecasing I54 of the pressure operated switch MI is connected to theservice valve 204, thereby connecting the emergency bellowsin directcommunication with the high pressurerefrigerant fluid line. This meansthat when the pressure of the high pressure refrigerant fluid lineexceeds a certain predetermined high value, the emergency bellowscontained in the casing I54 expands and intum operates the mercuryswitch I41 to shut off the electric motor I82. The circuit for'controlling the electric motor I82 may be treated as follows: Beginningwith the supply conductor I59, the current flows through the mercuryswitch I41 and thence back through a conductor I60 to the motor I82 andout to the supply line 202.

The upper temperature of the brine at which the motor I82 is started,and the lower tempera- I44, but the. value of the upper temperaturesetting is @termined by the adjustment of the large ture 'of the brineat which the motor I82 is stopped, is determined by the setting of thetoggle arrangement of the pressure actuated switch I4I.

In other words, the large -spring I43 determines spring I43. For verylow temperature, such as that encountered in an ice cream container, the'vapor pressure of the refrigerant in the evaporator of the flooded typeusually is negative; that is to say, the motor is shut off, for example,at 16 inches of vacuum, and'the motor is started at zero inches ofvacuum. These values, of course,

I96 through a pipe I51. The emergency bellows in depend on the nature ofthe refrigerant used. Therefore, it is to be understood that when theterm pressure is used, it covers both positive and negative pressures.

In Figure '7, I also illustrate a second flooded type of an evaporator,indicated generally by the reference character I for cooling arefrigerator compartment I16. For this type of service, the range oftemperatures at which the motor is started and at which the motor isstopped is in a higher bracket, than the range of temperatures at whichthe motor is started and stopped for operating the ice cream cabinet206. Thus, for

example, the temperature at which the motor is started with therefrigerator compartment I16 may correspond to eight pounds of pressure,and the temperature at which the motor is stopped may correspond toeight inches of vacuum. In order to operate two or more flooded types ofevaporators from the same compressor unit at difierent temperaturebrackets, I utilize the pressure actuated snap refrigerant valve H3. Theflow of the refrigerant from and to the evapora tor I15 may be traced asfollows: Beginning with the evaporator I15, the vapor refrigerant issucked through the pipe I33, the valve of the pressure actuated snapvalve mechanism II3, the service valve I98, and the pipe I99 to thecrank case of the compressor unit I8I. From here the refrigerant iscompressed and forced through the pipe I90 to the condenser I83, wherethe vapor refrigerant is liquefied and forced back to the evaporator I15through the service valve 2I3, the pipe I9I, a cleaner 234, the pipe232, the pipe I92, the service valve 205, and the pipe 200 to theevaporator I 15. This cycle of operation is continued so long as thepressure actuated snap valve mechanism H3 is open; provided, of course,that the compressor I8I is being operated. Let us assume that thecompressor I 8I is running, as it will be if the temperature of thebrine in the ice cream cabinet 205 is above itslower limit. Under therunning condition of the compressor I8I, the upper temperature bracketof theevapov rator I15 is determined by the setting of the large springH6 and the lower temperature bracket.

is determined by the setting of the small spring II1 of the pressureactuated valve mechanism II 3 see Figure 5. Thus, the pressure actuatedsnap valve mechanism II3 may be set 'to open the valve at eight poundspressure and allow the refrigerant to flow from the evaporator I15, andset to close the valve when the vapor pressure of the refrigerantdecreases to eight inches of vacuum. In other words, the togglearrangement of the pressure actuated valve mechanism I I3, is set for ahigher temperature bracket than the temperature bracket at which thetoggle arrangementfor the pressure actuating switch MI is set,Therefore, by the utilization of my pressure actuated snap valveassembly II3, I am able to operate two or more flooded types ofevaporators at diiierent temperature brackets from the same compressorunit. The setting of the toggle arrangement for the pressure actuatedsnap valve II3 may be such as to prevent too much ice collecting'on theevaporator. In other words, the evaporator I15 is ole-frosted each timethat the valve is closed.

In accordance with the current practice, the

flooded type of evaporator is being replaced by what is known in thetrade as a dry evaporator. Hence, if the customer desires to haveadditional refrigeration service from the same compressor, the presentpolicy is to install a dry flooded type of evaporator.

coil of pipes having fins I19 controlled by the thermo-expansion valveI80. In accordance with the practice of dry expansion evaporators, thereis installed a small thermo-expansion fluid tube I94 adjacent the exitpipe of the dry expansion evaporator, so that whatever ice is formed onthe pipe I18, cannot run back beyond the thermoexpansible fluid tubeI94, because just as soon as the ice reaches the thermo-expansible fluidtube I94, the expansible fluid therein contracts and operates to shutoff the expansion valve I80.

In the operation of a dry expansion evaporator, the pressure of therefrigerant is not a measure of the temperature, as is the case of aflooded type. The pressure of the vapor refrigerant, when thethermo-expansion valve I80 isbreathing, is substantially constant,regardless of the temperature conditions. Therefore, it is impossible tooperate a dry expansion evaporator by means of the pressure of the vaporrefrigerant, as is the case with the flooded type of evaporator.Accordingly, I utilize my thermally actuated snap valve mechanism,indicated generally by the reference character I to control the dryexpansion evaporator "8.. The circulation of the refrigerant for the dryexpansion evaporator I18 may be as follows: Beginning with theevaporator I18 the refrigerant is sucked to the compressor I8I throughthe pipe 20I, the service valve I98, the pipe I99 to the crank case ofthe compressor I8I. Here the vapor refrigerant is compressed and forcedthrough the pipe I90 to the evaporator I18 through the service valve2I3, the pipe I91, the cleaning device 234, the pipe 232, the pipe. toand through the valve of the thermo actuated snap valve mechanism I0,and-the pipe 32 to the expansion valve I80 which feeds the coils I18 ofthe dry expansion evaporator. This cycle of operation is continued solong as the thermally actuated snap valve mechanism I 0 is opened;provided the compressor unit I 8| is driven by the motor I82.

As illustrated, there is positioned adjacent the fins I19 of the dryexpansion evaporator, the thermo-expansible tube 31, which is connectedin communication with the thermally actuated snapvalve mechanism I0 bymeans of the pipe 38. This means that the thermally actuated snap valvemechanism III is controlled by the variable fluid pressure within thethermoexpansible tube 31. While the thermo-expansible tube 31 is mountedadjacent the fins I19, yet it is influenced by the temperature of thecirculating air within the refrigerator I11, as well as by the skintemperature of the fins I19. In the operation of a dry expansionevaporator, there is a tendency for the ice or frost to collect upon thefins, and if the frost or the ice were allowed to continue to collect,there would be formed a complete closure of ice around the fins I19.When this condition happens, the effective area of the cooling surfaceof the dry expansion evaporator is materially reduced, because thecirculating air can no longer contact the available space between thefins I19. Accordingly, it is to the dry expansion evaporator, such thatthe refrigerant is shut off when too much ice begins to collect on thefins I19. The refrigerant is kept shut off until the ice hassubstantially melted from the fins I19. Therefore, the thermallyactuated snap valve mechanism I0 is usually set to open the valve whenthe skin temperature of the fins I19 is at approximately 33 degrees,just above the melting point'of ice. For commercial purposes in order togive the proper refrigeration to the cooling of a refrigerator box, thelower 10 temperature at which the valve is set to close may beapproximately 16 degrees, skin temperature. With reference to thethermally actuated snap valve mechanism I0, the setting to give theupper 33 degrees skin temperature is determined by the tension of thelarge spring A and the setting to give the lower 16 degrees skintemperature is determined by the setting of the small spring B. It isalso noted that, just as soon as the ice begins to cover thethermo-expansible 2o fluid tube 31, the circulating air of therefrigerator box I11, which is of a higher temperature than the skintemperature of the fins I19, is isolated from the thermo-expansible tube31 itself, and thus under this condition, the thermally 9.0- tuated snapvalve mechanism. I0 operates to close the valve and stop the flow of therefrigerant at a slightly higher value than 16 degrees skin temperature.This means that just as soon as too much ice begins to form upon thefins I19, the tendency for the valve mechanism I0 to close earlier, ison the safe side. It is to be understood, however, that the range oftemperatures which I have assumed throughout this discussion is merelyarbitrary, and may vary for different servicing conditions, as well aswith the-kind of refrigerant utilized. In the actual practice, thetemperature bracket settings effected by the thermally actuated snapvalve mechanism l0 to control the dry expansion evaporator for therefrigerator box I11, may be substantially the same as the temperaturebracket settings effected by the pressure actuated refrigerant valve [I30 which controls the flooded'ftype of evaporator I15 for therefrigerator box I16. From the foregoing, it is noted that with theemployment of my several control devices, it is possible to controleither the flooded type or the dry expansion type of an evaporator, andoperate them at different temperature brackets for one compressor unit.For convenience, the thermally actuated snap valve mechanism I0, thepressure actuated snap valve I13, and the pressure actuated switch NI,may be mounted upon a panel I93.

In Figure 8, I show another use for my thermally actuated snap valve I0,in that it may be employed to control the cooling of the exit or gooseneck pipe 22I installed under a counter 2 I4 and controlled by a handvalve 2L5. As illustrated, the fluid or drink is fed by a pipe 1 I1 intothe container 2H3, where the container is usually refrigerated. If thefluid or drink is allowed to stand for any considerable length of timein the goose neck pipe 22L the drink becomes warm. Therefore, when adrink is served by operating the valve 2I5, the first few, customersreceive a warm drink. This is very objectionable. To overcome thisobjection, I provide for cooling the goose neck pipe 22L To this end, Iplace a strip of rubber tape 224 between the goose neck pipe HI and thefluid refrigerant cooling pipe 220 which contains the coolingrefrigerant and which is controlled by the thermo-expansion valve 2I9.The cooling or refrigerant pipe 220 and the goose neck pipe 22I, arewrapped with asbestos tape 16 225 to obtain efilcient operation. Thefluid refrigerant, as it is forced from the compressor and condenserflows through a pipe 222 and enters the thermally actuated snap valvemechanism III, and thence flows through the expansion valve 2 l 9, thefluid refrigerant pipe 220, the extra length of pipe 228 and outvthrough the pipe 223 to the crank case of the compressor unit. Thethermoexpansible fluid tube 31 is mounted within several loops of thecooling or refrigerant pipe 223,

Therefore, the amount of refrigerant delivered to .the cooling pipe 220to cool the goose neck pipe22l is determined by the setting of thethermally actuated snap valve mechanism III which keeps the drink cooledto the desired temperature. In this manner, the first few customers whoare served a drink, have a cool drink as well as the later servedcustomers. In accordance with usual practice, a thermlo-expansible fluidtube 226 is mounted adjacent the exit end of the extra length of pipes228, in order to prevent the ice running back on the pipe 223, becausewhen theice strikes the thermo-expansible fluid tube 226, the expansionvalve H9 is shut off. The operation and function of my thermo-actuatedsnap valve mechanism Ill in connection with this installation is thesame as that herein described with reference to the dry expansionevaporator I18 of Figure 7.

In Figure 10, I show a cleaning device adapted to clean the refrigerantand thereby keep the system free from as much trouble as possible. Inthe operation of a refrigerating system, there is a tendency for theforeign matter to collect upon the needle valve controlled by the floatof the "flooded type of evaporaton This prevents the proper operation ofthe evaporator. this difiiculty, I place my cleaning device in the fluidrefrigerant line in advance of the evaporator. a a

With'reference to Figure 10, the cleaning device is" designatedgenerally by the reference character 234, and comprises two flanges 235and 236 between which are placed two screens 240 and 262, between whichis placed a supply of ordinary absorbent cotton 2. A lead gasket 233 isplaced between the two fianges'in order to make a good tight seal, whenthe cap screws 243 are turned down. Screwed within the flange 235 is alower, plug 231 which receives the fluid pipe l9l and screwed in theupper flange 236 is an upper plug 236 which receives the pipe 232. The.screens have very fine mesh to prevent the larger foreign matter fromgoing therethrough. The action of ordinary absorbent cotton makes a verygood filter so that whatever small matter passes through the fine meshscreens is collected by the cotton. When the cleaning device has' beenin operation for a certain length of time, it may be dismantled andcleaned. In dismantling the cleaning device, all of the service valves2l3, I96, I96, 205 and 2M are closed, while the compressor sucks all ofthe refrigerant from the blanked pipes, after which the cleaning devicemay be dismantled, supplied with clean cotton, and re-installed in thesystem.

Although I have described my. invention with a certain degree ofparticularity, it is understood that the present disclosure has beenmade only by way of example and that numerous changes in the details ofconstruction and the combination and arrangement of parts may beresorted to without departing from the spirit and the scope of theinvention as hereinafter claimed,

To overcome I claim as my invention:

1. The combination with a container for holding a liquid, of a dischargefluid pipe extending from. the container, a valve for controlling thedischarge of the fluid from the fluid pipe, evaporator means includingan expansion valve for cooling the fluid contained in the dischargefluid pipe, said expansion valve beingof the breathing type and also ofthe type limiting the frost ing of the exit side of the evaporator, acontrol valve in series with the expansion valve for controlling thedelivery of the refrigerant to the expansion valve of the evaporatormeans, and thermally actuated means influenced by, I the evaporatormeans for controlling the control valve, said control valve includingsnap-action means for quicklyoperating said control valve.

2. A device for controlling the flowof refrigerant in an evaporatorhaving an-entrance and an exit side comprising, in combination, a valveconnected in communication with the evaporator for controlling the flowof refrigerant, means for controlling the valve to admit of an operatingcycle of the flow of the refrigerant in the evaporator in response tothe variation of the temperature at a given portion intermediate theentrance and exit side of the evaporator, and means to regulate theupper temperature at which the operating cycle of the flow of therefrigerant in the evaporator is initiated and the lower temperature atwhich the operating cycle is arrested.

3. A device for controlling the 'flow of refrigerant in an evaporatorhaving an entrance and an exit side comprising, in combination, a firstvalve connected in communication with the evaporator for controlling theflow of refrigerant, meansfor controlling the first valve to admit of anoperating cycle of the flow of the refriger-' ant through theevaporator'in response to the variation of the temperature at a givenportion intermediate the entrance and the exit side of the evaporator, asecond valve connected in communication with the evaporator forcontrolling the fiow of refrigerant, means for governing the secondvalve in response to the variation of the temperature at a given portionof the exit side of the evaporator to limit the frosting of the exitside of the evaporator in the direction of the flow of the refrigerant.

4. The combination with an evaporator arranged for inclusion in a closedcircuit for a refrigerant, of valve means connected in communicationwith the evaporator for controlling the flow of refrigerant, and meansincluding two temperature responsive means governed by the variation oftemperature at two spaced portions of the closed circuit for governingthe valve means, one of said responsive means being ar-, ranged to limitthe frosting of the exit side of the evaporator in the direction of theflow of the refrigerant and the other said responsive means beingarranged to admit of an operating cycle of the flow of the refrigerantin the evaporator.

5. The combination with an evaporator arranged for inclusion in a closedcircuit for a refrigerant, of first and second valve means connected incommunication with the evaporator for controlling the flow ofrefrigerant, a first temperature responsive device governed by thevariation of temperature of the evaporator for governing the first valvemeans, a second temsponsive means being arranged to limit the operatingcycle of the flow of the refrigerant in the evaporator.

6. The combination with an evaporator having an entrance and an exitside arranged for inclusion in a closed circuit for a refrigerant, ofvalve means connected in communication with the evaporator forcontrolling the flow of refrigerant, controlling means including atemperature responsive means governed by the variation of temperature ata given portion intermediate the entrance and the exit side of theevaporator for controlling the valve to admit of an operating cycle ofthe flow of the refrigerant in the evaporator, and means for causing thecontrolling means to operate and close the valve means and arrest theflow of the'operating cycle of the refrigerant at a temperaturesubstantially where the frost begins to collect on the saidintermegliate portion of the evaporator and to operate and open thevalve means and permit the flow of the operating cycle of therefrigerant at a temperature substantially where the frost 3 begins tomelt on said intermediate portion of the evaporator.

7. The combination with an evaporator having an entrance and an exitside arranged for in-- clusion in a closed circuit for a refrigerant, ofvalve means connected in communication with the evaporator, firsttemperature responsive means governed by the variation of thetemperature at a given portion of the exit side of the evaporator foroperating said valve means and limiting the frosting of the exit side ofthe evaporator in the direction of the flow of the refrigerant,snap-action valve means connected in communication with the'evaporatorfor controlling the flow of refrigerant, controlling means including asecond temperature responsive means governed by the variation of thetemperature at a given portion intermediate the entrance and the exitside of the evaporator for controlling the snap-action valve means toadmit of an operating cycle of the flow of the refrigerant in theevaporator, and means for causing the controlling means tooperate andquickly close the snapaction valve means and arrest the flow of theoperating cycle of the refrigerant at a temperature substantially wherethe frost begins to collect on the said intermediate portion of theevaponator and to operate and quickly open the said snap-action valvemeansand permit the flow of the operating cycle of the refrigerant at atemperature substantially where the frost begins to melt on saidintermediate portion of the evaporator. I r

' 8. The method of admitting a refrigerant to an evaporator whichcomprises regulating the admission of a refrigerant to the evaporator inaccordance with the .variation of pressure of the refrigerant enteringthe pressure side of the evaporator and with both the variation of thetemperature at a given portion of the exit side of the evaporator tolimit the frosting of the exit side of the evaporator in thedirection ofthe n of the refrigerant and the variation of the to perature at a givenportion of the evap orator in advance of the first-mentioned givenposition to admit of an operating cycle of the flow of the refrigerantin the evaporator.

9. The method of controlling a valve and the flow of refrigerant in aclosed circuit of a refrigerating system including an evaporator whichcomprises opening and closing the valve in acarcane cordance with ade-frosting cycle governed by the variation of the-temperature at agiven portion intermediate the exit and entrance sides of theevaporator. .l

10. In a refrigerating system having an evaporator, in combination,first valve means connected in communication with the evaporator forcontrolling the flow of the refrigerant, resilient means for urging-thevalve means in one direction to influence the operation of the valvemeans, flexible wall means for urging the valve means in the oppositedirection, first thermostatic bulb means connected in communication withthe flexible wall means and influenced by the variation of temperatureat a portion intermediate the entrance and exit side of the evaporatorfor controlling the first valve means, second valve means connected incommunication with the evaporator for controlling the flow of therefrigerant, and second thermostatic bulb means responsive means forinfluencing the operation of the valve means, each of the said twopressure responsive means being affected by the closed circuit at twospaced locations, one of said re sponsive means being arranged to limitthe frosting of the exit side of the evaporator in the direction of theflow of the refrigerant by its influence on one of said valves, and theother responsive means being arranged to admit of an operating cycle ofthe refrigerant by its influence on the other of said valve. i

12. In a refrigeration system having an evaporator arranged forinclusion in a closed refrigerant circuit, in combination, a valve forcontrolling the flow of refrigerant to said evaporator, pressureactuated means having opposed pressure means for operating said valve,said actuating means being actuated by the variable resultant pressureof said opposed pressure means, one opposed pressure means beingresponsive to and variable with the temperature at a portionintermediate the entrance and exit sides of the evaporator, the other ofsaid opposed pressure means being responsive to the pressure 'of therefrigerant and variable with the load on the evaporator.

13. In a refrigeration system having an evaporator arranged forinclusion in a closed refrigerant circuit, in combination, a valve forcontrolling the flow of refrigerant to said evaporator, pressureactuated means having opposed'pressure means for operating said valve,said actu,-

ating means being actuated by the variable resultant pressure of saidopposed pressure means, one opposed pressure means being responsive toand variable with the temperature at a portion intermediate the entranceand exit sides of the nication with said closed circuit and 10 meanshaving opposed pressure means for operating said valve, said actuatingmeans being actuated by the variable resultant pressure of said opposedpressure means, one opposed pressure means being responsive to andvariable with the temperature at a portion intermediate the entrance andexit sides of the evaporator, the other of said opposed pressure meansbeing in commuvariable with the load on the evaporator.

15. In combination with a fluid discharge conduit, a refrigeratingsystem including evaporator means for cooling said conduit, saidevaporator means being in heat transfer relation with the fluiddischarge conduit,a control valve for controlling the delivery of therefrigerant to the evaporator means, and thermally actuated meansinfluenced by the evaporator means for controlling the control valve toadmit of an operating cycle of the flow of the refrigerant in theevaporator means to cool the fluid discharge control valve to admit ofan operating cycle to the flow of said refrigerant, and second meansresponsive to the temperature of the evaporator means for operating saidsecond control valve to limit frosting on said evaporator means.

17. A refrigeration control device, comprising, in combination, a valvecasing, a valve mounted in the casing, flexible wall means for sealingthe valve in the casing, temperature responsive means disposedexternally of the flexible wall means to influence the operation of thevalve through the flexible wall means, and means to alter the influencethat the temperature responsive means has upon the operation of thevalve.

18. A regulating valve unit for an evaporator arranged for inclusion ina closed circuit for a refrigerant comprising, in combination, a valvecasing, a valve mounted in the casing, flexible means influenced byrefrigerant and enclosing the valve'within the casing, automatic meansarrangggd to transmit a motion through the flexible m operate the valve,said automatic means including a flexible wall means and a temperatureresponcasing, a valve mounted in the casing, flexible means influencedby refrigerant and enclosing the valve within the casing, automaticmeans arranged to transmit a motion through the flexible I means underthe influence ,of the refrigerant and operate the valve, said automaticmeans including a flexible wall means and a temperature responsivedevice filled with a thermo-expansible fluid. said temperatureresponsive device located s under the influence of the refrigerant andexternally of aportion intermediate the entrance and the exit side ofthe evaporator for controlling the valve to admit of an operating cycleto the flow of the refrigerant in the evaporator in accordance with ade-frosting cycle governed by the variation of the temperature at saidgiven loca-- means under the influence of the refrigerant and operatethe valve, said automatic means including a flexible wall means and atemperature responsive device filled with a thermo-expansible fluid,said temperature responsive device located externally of a portionintermediate the entrance and the exit side of the evaporator forcontrolling the valve to admit of an operating cycle to the flow of therefrigerant in the evaporator in accordance with a de-frosting cyclegoverned by the variation of the temperature at said given location ofthe temperature responsive device, and

equalizing means cooperatively associated with the valve and adapted tooff-set the internal pressure of the refrigerant upon the flexible meansto make the operation of the valvesubstantially independent of theinternal influence of the refrigerant acting upon the flexible means.

21. A device for controlling the flow of refrigerant in an evaporatorhaving an entrance and an exit side comprising, in combination, acontainer for holding a liquid, a discharge fluid pipe extending fromthe container and in heat transfer relation with the evaporator, meansfor controlling the discharge of the fluid from the fluid pipe, a firstvalve connected in communication with the evaporator for controlling theflow of refrigerant, means for controlling the first valve to admit ofan operating cycle of the flow of the refrigerant through the evaporatorin-response to the variation of the temperature at a given portionintermediate the entrance and the exit side of the evaporator, a secondvalve connected in communication with the evaporator for controlling theflow of refrigerant, means for governing the second valve in response tothe variation of the temperature at a given portion of the exit side ofthe evaporator to limit the frosting of the exit side of the evaporatorin the direction of the flow of the refrigerant.

22. A device foncontrolling the flow of refrigerant in an evaporatorhaving an entrance and an exit side comprising, in combination, a firstvalve means including a snap-action valve connected in communicationwith the evaporator for quickly controlling the flow of refrigerant,

means for controlling the first valve to admit of an operating cycle ofthe flow of the refrigerant through the evaporator in response to thevariation of the temperature at a given portion intermediate theentrance and the exit side of the evaporator, a second valve connectedin communication with the evaporator for controlling the flow ofrefrigerant, means for governing the side of the evaporator in thedirection of the flow of the refrigerant.

23. The combination with an evaporator arranged for inclusion in aclosed circuit for a refrigerant, of valve means including a snap-actionvalve connected in communication with the evap orator for quicklycontrolling the flow of refrigerant, and means including two temperatureresponsive means governed by the variation of temperature at two spacedportions of the closed circuit for governing the valve means, one ofsaid responsive means being arranged to limit the frosting of the exitside of the evaporator in the direction of the flow of the refrigerantand the other said responsive means being arranged to admit of anoperating cycle of the flow of the refrigerant in the evaporator.,

24. The method of controlling a valve and the flow of refrigerant in aclosed circuit of a refrigerating system including an evaporator whichcomprises quickly opening and quickly closing the valve in accordancewith a tie-frosting cycle aro aia governed by the variation ofthe-temperature at a given portion intermediate the exit and entrancesides of the evaporator 25. In combination with a fluid dischargeconduit, a refrigerating system for cooling said conciuit including anevaporator having an entrance and an exit side, said evaporator being inheat transfer relation with the fluid discharge con-\ duit, valve meansincluding a snap-action valve for controlling the delivery of therefrigerant to the evaporator, a first thermally actuated meansinfluenced by the variation in temperature at a given portionintermediate the entrance and the exit side of the evaporator forcontrolling the snap-action valve, and a second thermally actuated meansinfluenced by the variation in temperature at a given portion of theexit side of the evaporator for controlling-the said valve meansto admitof an operating cycle of the flow of the refrigerant in the evaporatorto cool the fluid discharge conduit.

' RUFUS E. STOLZ.

